1. Field of the Invention
The present invention relates to an imaging device and an image processing method, and specifically relates to an imaging device and an image processing method that perform point restoration processing of an image taken on the basis of PSF (Point Spread Function).
2. Description of the Related Art
Point restoration processing of a taken image is processing of finding the characteristic of degradation (PSF) due to the aberration or the like of a photographing lens beforehand and restoring the taken image (degraded image) to an original image of high resolution by performing filter processing by the use of a restoration filter created on the basis of the PSF.
PTL 1 (Japanese Patent Laid-Open No. 2011-211663) discloses an image processing apparatus that acquires an imaging state including a subject distance, acquires a restoration filter corresponding to the imaging state of each restoration region of a degraded image and restores the degraded image of each restoration region by the use of the degraded image and the restoration filter. The PSF varies according to the lens type, zoom magnification, f-number, subject distance and the angle of view (image height), and so on, and therefore it is necessary to prepare a lot of restoration filters.
The image processing apparatus described in PTL 1 includes a memory that holds multiple restoration filter lists corresponding to a combination of the lens type, zoom magnification and f-number. Each restoration filter list includes multiple restoration filter tables classified by the subject distance, and the restoration filter table holds a restoration filter (determinant of filter coefficients forming the restoration filter) for each image height (restoration region) (FIG. 3 of PTL 1).